/*
 * Copyright 2002-2005 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.util;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

/**
 * Web环境中，自定义Log4J初始化的引导监听器。<br/>
 * Bootstrap listener for custom Log4J initialization in a web environment.
 * Delegates to Log4jWebConfigurer (see its javadoc for configuration details).
 * 
 * <b>WARNING: Assumes an expanded WAR file</b>, both for loading the
 * configuration file and for writing the log files. If you want to keep your
 * WAR unexpanded or don't need application-specific log files within the WAR
 * directory, don't use Log4J setup within the application (thus, don't use
 * Log4jConfigListener or Log4jConfigServlet). Instead, use a global, VM-wide
 * Log4J setup (for example, in JBoss) or JDK 1.4's
 * <code>java.util.logging</code> (which is global too).
 * 
 * <p>
 * This listener should be registered before ContextLoaderListener in web.xml,
 * when using custom Log4J initialization.
 * 
 * <p>
 * For Servlet 2.2 containers and Servlet 2.3 ones that do not initalize
 * listeners before servlets, use Log4jConfigServlet. See the
 * ContextLoaderServlet javadoc for details.
 * 
 * @author Juergen Hoeller
 * @since 13.03.2003
 * @see Log4jWebConfigurer
 * @see Log4jConfigServlet
 * @see org.springframework.web.context.ContextLoaderListener
 * @see org.springframework.web.context.ContextLoaderServlet
 * @see WebAppRootListener
 */
public class Log4jConfigListener implements ServletContextListener {

	public void contextInitialized(ServletContextEvent event) {
		Log4jWebConfigurer.initLogging(event.getServletContext());
	}

	public void contextDestroyed(ServletContextEvent event) {
		Log4jWebConfigurer.shutdownLogging(event.getServletContext());
	}

}
